Begin by preparing the dough. Sift all ingredients together in a food processor (with the plastic dough attachment), except the egg and water. Pulse until you have a sandy consistency and the pieces of butter are pea size. Then place this mixture in a large bowl or not, you can continue in the food processor. Make a well in the middle and pour in the egg and water. Working with your hands or pulsing mix all ingredients together. It’ll get really sticky so little by little while mixing sprinkle the extra flour in the mixture until it becomes a dough. Make sure not to over mix the dough. Once you have a dough, plastic wrap it and place it in your freezer for 30 minutes.
Meanwhile, preheat oven to 375 degrees Farenheit.
Next, sprinkle some extra flour on your work surface to roll out dough. Roll the dough to the proper dimension. And gently drape it over the tin and fit into the bakeware. Trim off excesses dough around the tin. With a fork poke the bottom of the pie so it doesn’t rise when we pre bake it. On top put either pie weights or dried beans so there’s no rise. Place the tin on top of a baking sheet so it’s easier to put and take out of oven. Place pie crust in oven for 20 minutes. Then remove and set it aside to cool.
Now for Filling. Whisk the egg yolks and sugar together until it turns pale yellow, and set aside. In a small sauce pot bring the heavy cream, milk, and ground coffee to a boil, then set aside to cool. Once the coffee mixture is room temperature/cool while whisking add it in slowly into the egg yolk mixture. Then add in the ground cinnamon. Whisk everything well.
Lastly, cover bottom of the pie with the sliced bananas then pour over the filling and bake for approximately 30 min, or until pie is set. Remove from oven, and let it cool for 5-10 minutes before serving.